Yeah, I'm not a big fan of my electric one anymore either, so I'll change that if I'm going to mess around with modeling it. Definitely agree with you an the coloration Alysander, only I haven't worked out how to texture/paint properly in Zbrush yet so I'll need to work that out :) I'll give him some more whiskers too, and mess around with some flesh/scale texturization.

+ Big fold stretching on the bottom (blind creature eat rare, but much food)+ Noticeable sideline (as series of points/holes)

Not quite sure what you mean with the last two points though- could you please clarify?

Also is there any point in me doing this? As in, will this be able to be rigged to the slaughterfish skeleton later? I don't know anything about the technical restrictions, so if any of the other creature-modelers have any info about how I'd actually make this useful that would be great

Well, to make it useful you need to shoot for a reasonable tri count. If you have max and the niftools plugin, import the mesh of the slaughterfish (skyrim) and make sure that your model is not more than 150% the number of faces. If you started from a simple model in zbrush and divided up to your highest subdiv level, you can probably use your lowest subdiv model for the game model (if it's under the aforementioned limit.) The highpoly sculpt is really just used to create textures. Of course you can use decimation master to hit your target tri count, but do that before you use polypaint. If this is unclear, message me. You asked a very complicated answer, and I'm trying to give a concise answer.